1. Field of the Invention
This invention relates to novel oil soluble dispersants useful as additives in fuel and lubricating oil compositions, including concentrates containing said additives, and methods for their manufacture and use.
2. Description of the Prior Art
High molecular weight, oil soluble, mono- and poly-carboxylic acid esters, prepared by reaction of mono- or poly-carboxylic acid acylating reactants with the polyhydric alcohol pentaerythritol, have been prepared in the literature for use as dispersants in lubricants and fuels. Exemplary of these disclosures are U.S. Pat. Nos. 3,708,522 wherein esters of polyisobutenyl substituted succinic anhydride and pentaerythritol are post-treated with maleic anhydride to provide compositions useful as dispersants in lubricants and fuels. The reference also discloses that a preferred class of esters are prepared by reacting the mono- or polycarboxylic acid acylating reactants with aliphatic alcohol containing up to 10 carbon atoms, and that this class of alcohols includes glycerol, erythritol, pentaerythritol, gluconic acid, glyceraldehyde, glucose, arabinose, 1,7-heptanediol, 2,4-heptanediol, 1,2,3-hexanetriol, 1,2,4-hexanetriol, 1,2,5,-hexanetriol, 2,3,4,-hexanetriol, 1,2,3,-butanetriol, 1,2,4-butanetriol, quinic acid, 2,2,6,6-tetrakis-(hydroxymethyl)-cyclohexanol, 1,10-decanediol, and digitalose, and the like.
U.S. Pat. No. 3,533,945 relates to lubricating oil additives prepared by reaction of certain polyhydroxy compounds with recited amounts of a succinic acid producing compound, such as hydrocarbon substituted succinic acids or anhydrides thereof having at least 50 aliphatic carbon atoms in the hydrocarbon substituent, and at least about 1 mole of a boron reactant. The polyhydroxy compounds are recited to be substituted by more than one hydroxy group per hydrocarbon radical, and polyhydric alcohols disclosed include 1,2-cyclohexanediol and 1,3,5-cyclohexanetriol.
U.S. Pat. No. 4,209,411 relates to methylol poly ester derivatives of C.sub.12 to C.sub.22 hydrocarbon substituted succinic anhydride or acid which are the equimolar reaction products of the C.sub.12 to C.sub.22 hydrocarbon substituted succinic anhydride or acid and a cyclic poly(methylol) compound, which are disclosed to provide utility in fuels as rust inhibitors, in automatic transmission fluids as copper corrosion inhibitors, and in automotive, industrial and lubricating oils as sludge dispersants, rust inhibitors, friction reducers and copper alloy corrosion inhibitors. The cyclic poly(methylol) compounds are of the class consisting of 2,2,6,6-tetramethylol cyclohexanol, tetrahydro-3,3,5,5-tetrakis-(hydroxymethyl)-4-pyranol and tetrahydro-3,3,5-tris-(hydroxymethyl)-5-methyl-4-pyranol and have the generic structural formula as follows: ##STR2## wherein Y is --CH.sub.3 or --CH.sub.2 OH and X is --CH.sub.2 -- or --O--.